How to create a Realistic Moon
The best way to map the moon is to use an actual height map.  You can find a free usable map here: https://astrogeology.usgs.gov/search/details/Moon/LRO/LOLA/Lunar_LRO_LOLA_Global_LDEM_118m_Mar2014/cub

Nothing beats the real thing.  If you want to add more detail, use a noise displacement on top of it.